A dense plasma focus device is a plasma machine that produces, by electromagnetic acceleration and compression, short-lived plasma that is so hot and dense that the dense plasma focus device becomes a copious multi-radiation source. The basic dense plasma focus device was invented in the early 1960s by J. W. Mather and also independently invented by N. V. Filippov.
The standard Mather design for a dense plasma focus device is characterized by coaxial cylindrical anodes and cathodes. Since the inductance of the anode/cathode (“a/k”) assembly of the dense plasma focus device is a function of the ratio of the radii of the anode and the cathode, the “Mather” design is a constant inductance design.